One head told how she regularly carried out spot checks of prospective parents’ addresses to ensure they were not lying on application forms. Some parents have taken to “ratting” on each other if they suspect families are abusing the system. The spoiling tactics emerged as a survey revealed that 44 per cent of parents would fight dirty to get their children into a certain school.

According to the ICM poll of 800 parents, commissioned by Teachers’ TV, location was seen as a key factor in securing a place at a popular school.

Some 31 per cent said they would move to be near their first choice, 19 per cent said they were willing to rent a property closer to a favoured school, and 14 per cent would use an alternative address.

A further 12 per cent would lie about their religious beliefs to get into a school of their choice, the survey commissioned for the channel’s Big Debate programme said. Joseph Cullinane, an estate agent based in Hackney, east London, said: “Sometimes they do not even move in - they leave the property empty.”

But schools are fighting back. Dr Bev Feather, head of Clare House primary school, Beckenham, Kent, said this week: “I’ve looked through their letter boxes to see if there are piles of post and utility bills. Parents will also rat on other people, which is helpful.”

Dr Feather said parents caught abusing the system were refused entry, adding: “We say, ‘You’re busted. You do not have a place’.”

Mick Brookes, general secretary of the National Association of Head Teachers, said: “I’ve had colleagues, particularly in church schools, who have had to check addresses and found that children are using a grandparent’s house.”

The Big Debate can be downloaded from www.teachers.tv